Modern communications and data networks are comprised of nodes that transport data through the network. The nodes may include routers, switches, bridges, or combinations thereof that transport the individual data packets or frames through the network. Some networks may offer data services that forward data frames from one node to another node across the network without using pre-configured routes on intermediate nodes. Other networks may forward the data frames from one node to another node across the network along pre-configured or pre-established paths. Some networks implement Virtual Private Networks (VPNs), a scheme that logically interconnects remote (and often geographically separate) networks through public communication infrastructures, such as the Internet, or other core networks. Multicast VPN (MVPN) is a technology to deploy multicast services across existing VPNs or as part of a transportation infrastructure. A mechanism, such as a Protocol-Independent Multicast (PIM), may be used to carry MVPN multicast routing information and multicast traffic (at a data plane) and enable the flow of multicast traffic from the sources to the receivers.
A MVPN may be established using a core network, such as a Multiprotocol Label Switching (MPLS) core network, also referred to herein as a MPLS core. MPLS is a mechanism that directs data from one network node to the next based on short path labels instead of longer network addresses to avoid complex lookups in an address based routing table. The labels may identify virtual links (paths) between distant nodes rather than endpoints. In MPLS packets of various network protocols, such as Internet Protocol (IP) packets, may be encapsulated. The MVPN may be established to allow an enterprise to transparently interconnect a VPN across the MPLS core. As such, the MPLS core may serve as an overlay network for the MVPN, which may simplify MVPN control plane messaging and data plane packet forwarding.
A multicast Label Switched Path (mLSP) may be a shared MPLS tree that defines a plurality of paths used by a plurality of provider edge (PE) routers or nodes within the same MVPN domain to transport control messages and multicast data between one another. The mLSP may serve as a multicast distribution tree in a network and may be receiver initiated and Quality-of-Service (QoS) demanding. Setting up the mLSP efficiently in the network may be challenging due to multiple needed exchanges between the different components involved. Resource Reservation Protocol-Traffic Engineering (RSVP-TE) may be used in the setup of the multicast distribution tree to provide the QoS service required. However, RSVP-TE may need the knowledge of the locations of all receivers for the tree prior to the tree setup. Thus, a receiver discovery protocol may also be needed, such as a Border Gateway Protocol (BGP), to discover all the involved receivers. Further, a substantial number of PATH and RESV messages, as defined in the RSVP-TE protocol, may be exchanged during the tree setup, which may consume substantial network resources (e.g., bandwidth) and thus negatively affect performance.